A key function of appliance control is to provide for the safe operation of the appliance, even when a component failure in the appliance occurs. The consequences of a failure of a component within the appliance can be potentially severe. Not only can a failure damage other parts within the appliance, but the failure can result in serious injury to the user of the appliance.
For example, in the context of an oven, one component failure can cause the oven's heating element to turn on without temperature control. Also, when the oven is in the self-clean mode of operation, a component failure may unlock the door to an oven which has been heated to a hazardous temperature. Obviously, the failure of one component must not be allowed to turn the oven's heating element on or unlock the oven door.
Current appliance controls are costly to produce and are constructed from many discrete components which makes a control system costly to manufacture. Current safety control features also do not provide redundant control arrangements. In other words, current control systems do not provide for the system to continue to operate and detect unsafe operating conditions when a central component of the safety system fails.